The present invention relates to a method and an apparatus for orientation of fish upon a conveyor, by means of which the fish is transported lying in single file on random side, principally in parallel with the longitudinal direction of the conveyor.
In plants for processing fish there usually is a need for orientation of the fish in relation to the direction of conveyance, so that the fish is turned with its back- and belly side respectively in the same direction. Usually this orientation is accomplished by uprighting the fish from a position where it lies on either side, to a position where the fish stands vertically with the back side up. After this orientation, each fish can, if so desired, again be put down on the same side.
Prior art apparatuses for orientation of the in a file conveyed fish usually comprise a pair of rollers which are compliantly journalled upon vertical shafts, at a mutual distance principally corresponding to the width of the fish. Since many species of fish are more narrow at the belly side, a certain torque is generated on the fish about its longitudinal axis as it reaches into the nip of the pair of rollers.
However, this prior art method does not work for some species of white-fish, e.g. codfish, haddock and alaskan pollok, which have a more regular body shape with the same thickness at the back and belly side. These kinds of fish will be randomly uprighted with the back or belly side up.